The present study is an exploratory venture to possibly evaluate the role of calcium ions and therapeutic agents that block calcium channels in schizophrenia patients. Abnormalities in levels of Ca++ in the CSF have been observed in manic, depressed, and schizophrenia patients. We are in the process of quantitating levels of verapamil and its active metabolites - nor-verapamil in these patients. Both systemic and central levels of the drug and metabolite are being monitored by a recently modified (for enhanced sensitivity - (S/N N2) of 1 ng/ml) high performance liquid chromatographic assay which employs a eadial compression system. Information regarding assay validation and evaluation has been collected and variability appears to be below 10%. This new procedure will help us in quantitating low levels of the drug found in CSF.